Endoscopic surgical blade and method of use thereof

ABSTRACT

An endoscopic surgical blade is disclosed. The blade is of a low-profile design, having a downward angled cutting surface that is radiused at its upper end. The blade is part of an endoscopic knife assembly which also contains a knife tube. The endoscopic knife assembly is for use in endoscopic surgery by insertion of the assembly through a slotted cannula. The knife tube is hollow and allows the insertion of an endoscope for viewing of the surgical procedure. A method for a performing an operative procedure on a target tissue in a subject using an endoscopic knife assembly having a low-profile, downward angled blade is also described.

This application is a continuation application of U.S. patentapplication Ser. No. 13/410,392, filed Mar. 2, 2012. The entirety of theaforementioned application is incorporated herein by reference.

FIELD

This application generally relates to medical devices. In particular,the application relates to devices and methods for endoscopic surgery,e.g., for endoscopic trigger release surgery.

BACKGROUND

Endoscopic surgery is a minimally invasive surgical procedure that isperformed through small incisions or natural body openings. Anendoscopic procedure typically involves use of specialized devices andremote-control manipulation of instruments with indirect observation ofthe surgical field through an endoscope or similar device. Comparing toopen surgery, endoscopic surgery may result in shorter hospital stays,or allow outpatient treatment.

Trigger finger is characterized by catching, snapping or locking of theinvolved finger flexor tendon, associated with dysfunction and pain.Localized inflammation or nodular swelling of said flexor tendon causesa disparity in size between the flexor tendon and the surroundingretinacular pulley system, most commonly at the level of the firstannular (A1) pulley. When the subject extends the involved finger, thetendon will “catch” on the pulley, followed by an abrupt popping of thetendon through the pulley. This results in a difficulty flexing orextending the finger and the “triggering” phenomenon.

Typically, a first course of treatment for trigger finger iscorticosteroid injections into the tendon sheath to reduce inflammation.When corticosteroid injection is not or no longer effective, surgicaldivision of the A1 pulley is indicated. Conventional surgical techniquesfor trigger finger release require a fairly large incision over the A1pulley and spreading of the incision to allow viewing and instrumentaccess. These techniques can require a longer period of recovery thanendoscopic methods and have greater levels of post-operative pain due tothe incision size and level of manipulation during the procedure.Previous endoscopic techniques for trigger finger release require twoincisions, one proximal and one distal to the A1 pulley and thethreading of a cannula through the two incisions. An arthroscope is theninserted in the distal end of the cannula, while a cutting tool isinserted in the proximal opening. The cutting tool and arthroscope arethen alternately moved forward or backward through the cannula. Thisdoes not allow direct visualization of the procedure from the point ofview of the cutting tool during the separation of the pulley.Accordingly, the present application fulfils a need in the art for aminimally invasive surgical procedure for the treatment of triggerfinger by providing a method for uniportal endoscopic trigger releasesurgery and a low-profile endoscopic surgical blade with a downwardangled blade.

SUMMARY

One aspect of the present application relates to a low-profile blade foran endoscopic knife assembly, comprising a cutting surface at its distalend that is angled downward and having a non-cutting radiused surface atthe top end of the cutting surface, wherein the blade is sized to fit ata tip of an endoscope.

Another aspect of the present application relates to an endoscopic knifeassembly, comprising: a knife tube having a distal end and a proximateend and a low-profile blade that has a downward angled cutting surfacethat is radiused at its upper end attached to the distal end.

Another aspect of the present application relates to an instrument kitfor implementing an endoscopic surgical procedure comprising: anendoscopic knife assembly comprising a low-profile blade that has adownward angled cutting surface that is radiused at its upper end and aknife tube.

Another aspect of the present application relates to a method fortreating trigger finger, comprising: establishing an entry portal at alocation proximal to the A1 pulley, inserting a cannula having openproximal and distal ends and an open slot extending along the length ofthe cannula, inserting an endoscope into the cannula, said endoscopecomprising an endoscopic knife assembly having a low-profile blade thathas a downward angled cutting surface that is radiused at its upper end,advancing said endoscope so that the blade moves in contact with the A1pulley through the slot, operatively engaging the A1 pulley with theblade, and advancing the blade through the cannula to divide the A1pulley.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention can be better understood by reference to thefollowing drawings. The drawings are merely exemplary to illustratecertain features that may be used singularly or in combination withother features and the present invention should not be limited to theembodiments shown.

FIGS. 1A-D illustrate a blade component of an endoscopic knife assembly.FIG. 1A depicts a side view of the blade component, showing the cuttingsurface, the transition where the blade is joined to a knife tube andthe taper at the end of the blade. FIG. 1B is a cross section view ofthe blade at the bisecting line X-X in FIG. 1A depicting an exemplaryangle of a cutting surface of the blade component. FIG. 1C is aperspective view of the blade from the back depicting the width of theblade and the transition. FIG. 1D depicts a side view of anotherembodiment of the blade component.

FIGS. 2A-C illustrate another embodiment of a blade component of anendoscopic knife assembly. FIG. 2A depicts a side view of the bladecomponent, showing the cutting surface, the transition where the bladeis joined to a knife tube and the taper at the end of the blade. FIG. 2Bis a cross section view of the blade at the bisecting line X-X in FIG.2A depicting an exemplary angle of a cutting surface of the bladecomponent. FIG. 2C is a perspective view of the blade from the backdepicting the width of the blade and the transition.

FIGS. 3A-E illustrate an endoscopic knife assembly for manual operation.FIG. 3A is a perspective view of the endoscopic knife assembly fromabove, without a locking nut. FIG. 3B is a perspective view of theendoscopic knife assembly from the side, including a locking nut. FIG.3C is a cross section view of the endoscopic knife assembly and lockingnut at the bisecting line Y-Y in FIG. 3B, as viewed in the direction ofthe arrows. FIG. 3D is a perspective view of the endoscopic knifeassembly from the distal end. FIG. 3E is a perspective view of theendoscopic knife assembly from the proximate end.

FIGS. 4A-D illustrate the a knife tube component of an endoscopic knifetube for manual operation. FIG. 4A is a three-dimensional perspectiveview of a knife tube at an angle. FIG. 4B is a perspective view of theknife tube, showing the slots and a handle. FIG. 4C is a perspectiveview of the knife tube rotated 90 degrees from the view in FIG. 4B,showing the slots and a handle. FIG. 4D is a cross section view of theendoscopic knife tube and handle at the bisecting line Z-Z in FIG. 4C,as viewed in the direction of the arrows.

FIGS. 5A-D illustrate an endoscopic knife assembly. FIG. 5A is aperspective view of the endoscopic knife assembly from the side. FIG. 5Bis a perspective view of the endoscopic knife assembly from the top.FIG. 5C is a perspective view of the endoscopic knife assembly from thebottom. FIG. 5D is a perspective view of the endoscopic knife assemblyfrom the distal end.

FIGS. 6A-D illustrate another embodiment of an endoscopic knifeassembly. FIG. 6A is a perspective view of the endoscopic knife assemblyfrom the side. FIG. 6B is a perspective view of the endoscopic knifeassembly from the top. FIG. 6C is a perspective view of the endoscopicknife assembly from the bottom. FIG. 6D is a perspective view of theendoscopic knife assembly from the distal end.

FIGS. 7A-C are perspective views of a knife tube without an affixedblade or alignment ring and without gradations.

FIGS. 8A-D illustrate the alignment ring component of the endoscopicknife assembly of FIGS. 5A-D and 6A-D. FIG. 8A is a perspective view atan angle as seen from the bottom, showing the flattened bottom face ofthe alignment ring. FIG. 8B is a perspective view at an angle as seenfrom the front or back face of the alignment ring. FIG. 8C is aperspective view seen from the side of the alignment ring. FIG. 8D is aperspective view seen from the top of the alignment ring.

FIGS. 9A-B depict the visualization of the A1 and A2 pulleys in auniportal endoscopic trigger finger release surgical procedure.

FIGS. 10A-B depict the direct viewing of the division of the A1 pulleyduring a uniportal endoscopic trigger finger release surgical procedure.

FIGS. 11A-B depict the visualization of the cut ends of the A1 pulleyand of the underlying flexor tendon during a uniportal endoscopictrigger finger release surgical procedure.

DETAILED DESCRIPTION

The following detailed description is presented to enable any personskilled in the art to make and use the invention. For purposes ofexplanation, specific nomenclature is set forth to provide a thoroughunderstanding of the present invention. However, it will be apparent toone skilled in the art that these specific details are not required topractice the invention. Descriptions of specific applications areprovided only as representative examples. The present invention is notintended to be limited to the embodiments shown, but is to be accordedthe widest possible scope consistent with the principles and featuresdisclosed herein.

The present application generally relates to endoscopic surgical deviceand method for endoscopic trigger release surgery.

This description is intended to be read in connection with theaccompanying drawings, which are to be considered part of the entirewritten description of this application. The drawing figures are notnecessarily to scale and certain features of the application may beshown exaggerated in scale or in somewhat schematic form in the interestof clarity and conciseness. In the description, relative terms such as“front,” “back,” “up,” “down,” “top,” “bottom,” “upper,” “lower,”“distal,” and “proximate” as well as derivatives thereof, should beconstrued to refer to the orientation as then described or as shown inthe drawing figure under discussion. These relative terms are forconvenience of description and normally are not intended to require aparticular orientation. Terms concerning attachments, coupling and thelike, such as “connected,” “mounted,” and “attached,” refer to arelationship wherein structures are secured or attached to one anothereither directly or indirectly through intervening structures, as well asboth movable or rigid attachments or relationships, unless expresslydescribed otherwise.

The term “trigger finger,” as used herein, also refers to “triggerdigit,” “trigger thumb,” and “stenosing tendovaginitis.”

The blade described herein is a low-profile blade that has a downwardangled cutting surface that is radiused at its upper end to preventdamage to the underlying tendon during the separation of the A1 pulley.This downward angle allows the blade described herein to maintain a lowprofile such that it can be used with a slotted cannula for the precisedivision of the A1 pulley.

The presently described low-profile blade is sized to fit at the tip ofan endoscope and form a component of an endoscopic knife assembly,wherein the blade is welded onto a hollow knife tube that allows thepractitioner to extend an endoscopic camera through the hollow knifetube to allow direct visualization of the tissue and blade before,during and after the cutting of the target tissue. Particularembodiments of the endoscopic knife assembly further comprise a handleat its proximal end that allows the direct manual manipulation of theendoscopic knife assembly. The handle also comprises a hollow lumen thatallows an arthroscope to be passed through the handle into the knifetube, allowing direct visualization of the tissue and blade before,during and after the cutting of the target tissue. Other embodiments ofthe knife tube assembly comprise an alignment ring and slots at theproximate end to allow the knife tube assembly to be mated with thelocking mechanism of an endoscopic surgical system.

One aspect of the present application relates to a low-profile blade foran endoscopic knife assembly, comprising a cutting surface at its distalend that is angled downward and having a non-cutting radiused surface atthe top end of the cutting surface. As used herein, the term“low-profile” means that the body of the blade does not protrude morethan 2.5 mm through the slot on a slotted cannula.

In one particular embodiment, the downward angle of the cutting surface,which is defined as shown in FIGS. 5 and 6 is between about 25 degreesand about 50 degrees. In a more particular embodiment, the downwardangle is between about 30 degrees and about 45 degrees. In a still moreparticularly embodiment, the downward angle is between about 30 degreesand about 40 degrees. In a further embodiment, the downward angle isabout 36 degrees. In another further embodiment, the downward angle isabout 30 degrees.

In one particular embodiment, the proximate section of the blade bodyhas a tapered end.

In another particular embodiment, the blade body comprises a notch onthe lower edge to engage with a knife tube.

In another particular embodiment, the blade has a total vertical heightin the range of about 1.8 mm to about 2.6 mm.

Another aspect of the present application relates to an endoscopic knifeassembly, comprising: a knife tube having a distal end and a proximateend and a low-profile blade that has a downward angled cutting surfacethat is radiused at its upper end attached to the distal end.

In a further embodiment, the endoscopic knife assembly further comprisesa handle at the proximal end of the knife tube.

In a still further embodiment, the handle comprises compression fingersfor gripping the knife tube and a threaded region for the attachment ofa clamping nut.

In another still further embodiment, the handle is bonded to the knifetube. In a related embodiment the handle is bonded with epoxy.

In another further embodiment, the knife tube comprises an alignmentring attached near the proximate end and one or more slots at theproximate end for the attachment of a locking assembly to the knife tubeand alignment ring.

In related embodiment, the slots are located on a plane that isperpendicular to the blade attached to the distal end of the knife tube.

In another related embodiment, the alignment ring comprises a flattenedsurface that is positioned perpendicular to the hook blade attached tothe distal end of the knife tube.

In another particular embodiment, the knife tube is marked on the top orside surface with gradations.

In another particular embodiment, the blade is welded to the knife tube.

Another aspect of the present application relates to an instrument kitfor implementing an endoscopic surgical procedure comprising: anendoscopic knife assembly comprising a low-profile blade that has adownward angled cutting surface that is radiused at its upper end and aknife tube.

In a further embodiment, the endoscopic knife assembly further comprisesa handle at the proximal end of the knife tube.

In a still further embodiment, the handle comprises compression fingersfor gripping the knife tube and a threaded region for the attachment ofa clamping nut.

In another still further embodiment, the handle is bonded to the knifetube. In a related embodiment the handle is bonded with epoxy.

In another further embodiment, the knife tube comprises an alignmentring attached near the proximate end and one or more slots at theproximate end for the attachment of a locking assembly to the knife tubeand alignment ring.

In another further embodiment, the kit further comprises a cannulahaving an open slot extending along the length of the cannula.

In another particular embodiment, the cannula is a clear cannula.

In another further embodiment, the kit further comprises an obturator.

In another further embodiment, the kit further comprises an elevator.

In another further embodiment, the kit further comprises an arthroscope.

Another aspect of the present application relates to a method for aperforming an operative procedure on a target tissue in a subject,comprising: establishing an entry portal, inserting a cannula havingopen proximal and distal ends and an open slot extending along thelength of the cannula, inserting an endoscope into the cannula, saidendoscope comprising an endoscopic knife assembly having a low-profileblade that has a downward angled cutting surface that is radiused at itsupper end, advancing said endoscope so that the blade moves in contactwith the target tissue through the slot, operatively engaging the targettissue with the blade, and advancing the blade through the cannula todivide the target tissue.

In one particular embodiment, the operative procedure is trigger fingerrelease.

In another particular embodiment, the establishing an entry portalcomprises making an incision.

In another particular embodiment, the target tissue is the A1 pulley.

In another particular embodiment, the inserting of said endoscopecomprising an endoscope comprising an endoscopic knife assembly having alow-profile blade that has a downward angled cutting surface that isradiused at its upper end is preceded by the insertion of anotherendoscope comprising a means for visualization of the target tissue.

In a particular embodiment, the cannula is a clear cannula. In a furtherembodiment, the method further comprises visualization of anatomicstructures surrounding the cannula.

One aspect of the present invention relates to a low-profile downwardangled endoscopic surgical blade. The design of the present blade issuch that it is usable in endoscopic surgery in a manner that allows thepractitioner to extend the blade through the cannula to the targettissue without damage to surrounding tissue and/or organs. The blade ismade from materials commonly used for surgical blades or scalpels, suchmaterials include, but are not limited to, hardened and tempered steel,stainless steel, high carbon steel, titanium, alloys and ceramic.

In particular embodiments, the blade is made from stainless steel. In afurther embodiment, the stainless steel is martensitic stainless steel.An exemplary martensitic stainless steel is Bohler-Uddeholm AEB-Lmartensitic stainless steel. In a still further embodiment, themartensitic stainless steel is heat-treated. In another furtherembodiment, the stainless steel is 440 A stainless steel. In aparticular embodiment, the blade is made from Hitachi GIN-5 SST-MODIFIED440-A stainless steel. The blade is optionally flash electropolished.The cutting edges are machine finished and must be sharp. In aparticular embodiment, the steel of the blade is heat-treated toRockwell C hardness of about 50-72. In a more particular embodiment, thesteel of the blade is heat-treated to Rockwell C hardness of 58-64.

FIG. 1A depicts a side view of the blade component of the endoscopicknife assembly, showing the cutting surface at the leading end of theblade, the transition where the blade is joined to the knife tube andthe taper at the trailing end of the blade.

FIG. 1B is an view depicting an exemplary angle of the cutting surfaceof the blade as viewed from the perspective of the line X-X in FIG. 1A.

FIG. 1C is a perspective view of the blade from the back depicting thewidth of the blade and the transition between the mounting surface andthe lower end of the cutting surface below the transition.

FIG. 1D depicts a side view of another embodiment of the bladecomponent.

In a particular embodiment, the blade 100 as shown in FIG. 1A comprisesa cutting surface 1 on the leading end of the blade, which is at anangle 2 with respect to the horizontal orientation of the blade 100, asdefined by the mounting surface 3 of the blade. The angle 2 is such thatthe top of cutting surface 1 is forward of the bottom of the cuttingsurface. In one embodiment the angle 2 is between about 30 and about 45degrees. In a particular embodiment, the angle 2 is between about 33 andabout 39 degrees. In a more particular embodiment, the angle 2 is about36 degrees.

In some embodiments, the upper end 4 of the cutting surface 1 isradiused. The radiused upper end 4 of the cutting surface 1 is about 90degrees of a circle and has a radius measurement between about 0.50 mmand 1.50 mm. In a particular embodiment, the radius is about 0.94 mm.

In some embodiments, the cutting surface 1 has a vertical height 13between about 0.80 mm and about 1.70 mm. In particular embodiments, thevertical height 13 is between about 1.00 mm and 1.50 mm. In a moreparticular embodiment, the vertical height 13 is about 1.27 mm.

In a particular embodiment, the total length 5 of the blade from theleading point of the cutting surface 1 to the trailing end of the bladeis between about 13 mm and about 21 mm. In another particularembodiment, the total length 5 of the blade from the leading point ofthe cutting surface to the trailing end of the blade is between about 15mm and about 19 mm. In a more particular embodiment the total length 5of the blade is about 16.69+/−0.254 mm. In a particular embodiment, thelength 5 a of the forward section of the blade from the leading point ofthe cutting surface 1 to the leading edge of the notch 7 is betweenabout 2 mm and about 8 mm. In another particular embodiment, the length5 a of the forward section of the blade from the leading point of thecutting surface to the leading edge of the notch 7 is between about 3 mmand about 5 mm. In a more particular embodiment the length 5 a of theforward section of the blade is about 4+/−0.254 mm.

In order to insure that, during manufacture, the blade is consistentlyjoined to the knife tube in the same location, the lower surface of themain body of the blade comprises a transition 6, the distal end of whichmeets the notch 7 in the lower surface of the main body of the blade.During assembly of the endoscopic knife assembly, the mounting surface 3is aligned with and positioned on the forward end of the knife tube.Following the positioning of the blade on the knife tube, the blade islaser welded all around to the knife tube. In a particular embodiment,the strength of the weld is tested by applying torque to the unit, forexample about 10 in-lbs of torque. In a first embodiment, the depth ofthe transition 6 is between about 0.03 mm and about 0.18 mm. In aparticular embodiment, the depth of the transition 6 is between about0.05 mm and about 0.15 mm. In a more particular embodiment, the depth ofthe transition 6 is about 0.10 mm.

In particular embodiments, the blade further comprises a notch 7 on thelower edge of the blade between the mounting surface 3 and the cuttingsurface 1. In particular embodiments, the notch 7 is relativelysemi-circular in shape, having a radius of between about 0.1 mm andabout 0.3 mm, more particularly about 0.18 mm. The top of the notch 7 isrecessed 10 into the body of the blade, with respect to the bottom endof the cutting surface 1, between about 0.1 mm and about 0.3 mm, moreparticularly about 0.18 mm.

In particular embodiments, the horizontal distance 14 between the bottomof the leading edge of the cutting surface 1 and the notch 7 can bedifferent, dependent upon the application for the blade. In someembodiments, the horizontal distance is between about 1.50 mm and about2.50 mm. In a more particular embodiment, the horizontal distance 14 isabout 1.80 mm, as exemplified in FIG. 1A. In another more particularembodiment, the horizontal distance 14 is about 2.26 mm, as exemplifiedin FIG. 1D.

In order to prevent the blade from catching on tissues or a cannula whenthe blade is drawn backwards through a cannula tube, the trailing edge 8of the blade is angled down to the knife tube and the top of thetrailing edge 8 is radiused 9. In a particular embodiment, the verticalheight of the trailing edge 8 is between about 0.50 mm and about 0.88mm, more particularly about 0.60 mm to about 0.70 mm. In a moreparticular embodiment, the vertical height of the trailing edge 8 isabout 0.66 mm. In some embodiments, the radius 9 at the top of thetrailing edge 8 is between about 0.40 mm and about 0.80 mm. In furtherembodiments, the radius 9 at the top of the trailing edge 8 is betweenabout 0.50 mm and about 0.70 mm, more particularly about 0.61 mm.

In some embodiments the trailing edge 8 is canted forward at an angle 11from the vertical with respect to the horizontal line of the mountingsurface 3. in particular embodiments, the forward angle 11 of thetrailing edge 8 is between about 30 degrees and about 90 degrees. Infurther embodiments, the angle 11 is between about 45 degrees and about85 degrees. In more particular embodiments, the angle 11 is betweenabout 65 degrees and about 80 degrees. In a most particular embodiment,the angle 11 is about 75 degrees.

In some embodiments, the top edge 12 of the blade 100 forms an angle 19with respect to bottom edge 3, sloping downward as defined by FIG. 1Afrom where it meets the radius 4 at the top of cutting surface 1 towhere it meets the radius 9 at the top of the trailing edge 8. Inparticular embodiments, the angle 19 of the top edge 12 is between about2.5 degrees and about 10 degrees. In more particular embodiments, theangle 19 of the top edge 12 is between about 3.5 degrees and about 7degrees. In a still more particular embodiment, the angle 19 of the topedge is about 5 degrees.

Referring now to FIG. 1B, the cutting surface 1 is a single beveledcutting surface and the angle 15 is between about 30 degrees and about50 degrees. In some embodiments, the angle 15 is between about 35degrees and about 45 degrees. In a particular embodiment, the angle 15is about 40 degrees.

Referring to FIG. 1C, in a particular embodiment, the height 17 of thebody of the blade is between about 1.8 mm and about 2.6 mm. In anotherembodiment, the height 17 of the body of the blade is between about 2.1mm and about 2.3 mm. In a particular embodiment, the height 17 of thebody of the blade is between about 2.15 mm and about 2.23 mm. In a moreparticular embodiment, the height 17 of the body of the blade is about2.18+/−0.25 mm.

Again referring to FIG. 1C, in a particular embodiment, the width 18 ofthe body of the blade is between about 0.3 mm and about 0.9 mm. Inanother embodiment, the width 18 of the body of the blade is betweenabout 0.45 mm and about 0.75 mm. In a particular embodiment, the width18 the body of the blade is about 0.64+/−0.25 mm.

FIG. 2A depicts a side view of another embodiment of the blade componentof the endoscopic knife assembly, showing the cutting surface at theleading end of the blade, the transition where the blade is joined tothe knife tube and the taper at the trailing end of the blade.

FIG. 2B is an view depicting an exemplary angle of the cutting surfaceof the blade as viewed from the perspective of the line X-X in FIG. 2A.

FIG. 2C is a perspective view of the blade in FIG. 2A from the backdepicting the width of the blade and the transition between the mountingsurface and the lower end of the cutting surface below the transition.

In a particular embodiment, the blade 100 as shown in FIG. 2A comprisesa cutting surface 1 on the leading end of the blade, which is at anangle 2 with respect to the horizontal orientation of the blade 100, asdefined by the mounting surface 3 of the blade. The angle 2 is such thatthe top of cutting surface 1 is forward of the bottom of the cuttingsurface. In one embodiment the angle 2 is between about 20 and about 40degrees. In a particular embodiment, the angle 2 is between about 25 andabout 35 degrees. In a more particular embodiment, the angle 2 is about30 degrees.

In some embodiments, the upper end 4 of the cutting surface 1 isradiused. The radiused upper end 4 of the cutting surface 1 is about 90degrees of a circle and has a radius measurement between about 0.50 mmand 1.50 mm. In a particular embodiment, the radius is about 0.94 mm.

In some embodiments, the cutting surface 1 has a vertical height 13between about 0.80 mm and about 1.70 mm. In particular embodiments, thevertical height 13 is between about 1.00 mm and 1.50 mm. In a moreparticular embodiment, the vertical height 13 is about 1.27 mm.

In a particular embodiment, the total length 5 of the blade from theleading point of the cutting surface 1 to the trailing end of the bladeis between about 13 mm and about 21 mm. In another particularembodiment, the total length 5 of the blade from the leading point ofthe cutting surface to the trailing end of the blade is between about 15mm and about 19 mm. In a more particular embodiment the total length 5of the blade is about 16.69+/−0.254 mm. In a particular embodiment, thelength 5 a of the forward section of the blade from the leading point ofthe cutting surface 1 to the leading edge of the notch 7 is betweenabout 2 mm and about 8 mm. In another particular embodiment, the length5 a of the forward section of the blade from the leading point of thecutting surface to the leading edge of the notch 7 is between about 3 mmand about 5 mm. In a more particular embodiment the length 5 a of theforward section of the blade is about 4+/−0.254 mm.

In order to insure that, during manufacture, the blade is consistentlyjoined to the knife tube in the same location, the lower surface of themain body of the blade comprises a transition 6, the distal end of whichmeets the notch 7 in the lower surface of the main body of the blade.During assembly of the endoscopic knife assembly, the mounting surface 3is aligned with and positioned on the forward end of the knife tube.Following the positioning of the blade on the knife tube, the blade islaser welded all around to the knife tube. In a particular embodiment,the strength of the weld is tested by applying torque to the unit, forexample about 10 in-lbs of torque. In a first embodiment, the depth ofthe transition 6 is between about 0.03 mm and about 0.18 mm. In aparticular embodiment, the depth of the transition 6 is between about0.05 mm and about 0.15 mm. In a more particular embodiment, the depth ofthe transition 6 is about 0.10 mm.

In particular embodiments, the blade further comprises a notch 7 on thelower edge of the blade between the mounting surface 3 and the cuttingsurface 1. In particular embodiments, the notch 7 is relativelysemi-circular in shape, having a radius of between about 0.1 mm andabout 0.3 mm, more particularly about 0.18 mm. The top of the notch 7 isrecessed 10 into the body of the blade, with respect to the bottom endof the cutting surface 1, between about 0.1 mm and about 0.3 mm, moreparticularly about 0.18 mm.

In particular embodiments, the horizontal distance 14 between the bottomof the leading edge of the cutting surface 1 and the notch 7 can bedifferent, dependent upon the application for the blade. In someembodiments, the horizontal distance is between about 1.50 mm and about2.50 mm. In further embodiments, the horizontal distance is betweenabout 1.65 mm and about 2.0 mm. In a more particular embodiment, thehorizontal distance 14 is about 1.80 mm.

In order to prevent the blade from catching on tissues or a cannula whenthe blade is drawn backwards through a cannula tube, the trailing edge 8of the blade is angled down to the knife tube and the top of thetrailing edge 8 is radiused 9. In a particular embodiment, the verticalheight of the trailing edge 8 is between about 0.50 mm and about 0.88mm, more particularly about 0.60 mm to about 0.70 mm. In a moreparticular embodiment, the vertical height of the trailing edge 8 isabout 0.66 mm. In some embodiments, the radius 9 at the top of thetrailing edge 8 is between about 0.40 mm and about 0.80 mm In furtherembodiments, the radius 9 at the top of the trailing edge 8 is betweenabout 0.50 mm and about 0.70 mm, more particularly about 0.61 mm.

In some embodiments the trailing edge 8 is canted forward at an angle 11from the vertical with respect to the horizontal line of the mountingsurface 3. in particular embodiments, the forward angle 11 of thetrailing edge 8 is between about 30 degrees and about 90 degrees. Infurther embodiments, the angle 11 is between about 45 degrees and about85 degrees. In more particular embodiments, the angle 11 is betweenabout 65 degrees and about 80 degrees. In a most particular embodiment,the angle 11 is about 75 degrees.

In some embodiments, the top edge 12 of the blade 100 forms an angle 19with respect to bottom edge 3, sloping downward as defined by FIG. 2Afrom where it meets the radius 4 at the top of cutting surface 1 towhere it meets the radius 9 at the top of the trailing edge 8. Inparticular embodiments, the angle 19 of the top edge 12 is between about2.5 degrees and about 10 degrees. In more particular embodiments, theangle 19 of the top edge 12 is between about 3.5 degrees and about 7degrees. In a still more particular embodiment, the angle 19 of the topedge is about 5 degrees.

Referring now to FIG. 2B, in some embodiments, the cutting surface 1 isground to form a double beveled surface over its depth 16. In particularembodiments, the cutting surface 1 has a depth 16 of between about 1.0mm and about 2.0 mm. In further particular embodiments, the cuttingsurface 1 has a depth 16 of between about 1.25 mm and about 1.75 mm. Inmore particular embodiments, the cutting surface 1 has a depth 16 ofabout 1.5 mm. In particular embodiments, the double beveled cuttingsurface 1 is ground to comprise a first angle 15 a over its depth 16 ofbetween about 5 degrees and about 30 degrees. In further embodiments,the first angle 15 a is between about 12 degrees and about 22 degrees.In a more particular embodiment, the first angle 15 a is about 17degrees.

In some embodiments, the double beveled cutting surface 1 is groundagain over the depth of its leadingmost edge 20 to a second angle 15 b.In particular embodiments, the leadingmost edge 20 of cutting surface 1has a depth of between about 0.05 mm and about 0.4 mm. In furtherparticular embodiments, the leadingmost edge 20 of cutting surface 1 hasa depth of between about 0.1 mm and about 0.3 mm. In more particularembodiments, the leadingmost edge 20 of cutting surface 1 has a depth ofabout 0.2 mm.

In particular embodiments, the leadingmost edge 20 of double beveledcutting surface 1 is ground to comprise a second angle 15 b over itsdepth of between about 20 degrees and about 45 degrees. In furtherembodiments, the second angle 15 b is between about 25 degrees and about36 degrees. In a more particular embodiment, the second angle 15 b isabout 31 degrees.

Referring to FIG. 2C, in a particular embodiment, the height 17 of thebody of the blade is between about 1.8 mm and about 2.6 mm. In anotherembodiment, the height 17 of the body of the blade is between about 2.1mm and about 2.3 mm. In a particular embodiment, the height 17 of thebody of the blade is between about 2.15 mm and about 2.23 mm. In a moreparticular embodiment, the height 17 of the body of the blade is about2.18+/−0.25 mm.

Again referring to FIG. 2C, in a particular embodiments, the width 18 ofthe body of the blade is between about 0.3 mm and about 0.9 mm. Inanother embodiment, the width 18 of the body of the blade is betweenabout 0.45 mm and about 0.75 mm. In a more particular embodiment, thewidth 18 the body of the blade is about 0.5+/−0.25 mm. In a still moreparticular embodiment, the width 18 the body of the blade is about0.51+/−0.03 mm.

The blade 100 is affixed onto a knife tube, such as, but not limited to,those exemplified in FIGS. 3-7.

In some embodiments, as exemplified in FIGS. 3A-E, the knife tube ispart of a handheld endoscopic knife assembly, having at least a blade100, a knife tube 200 and a handle. In some embodiments, the knife tube200 comprises slits 21 in the tube for proper alignment of the tube inthe handle 22, as shown in FIG. 3A. In particular embodiments, the knifetube 200 is held in the handle 22 by means of friction and/or pressure.For example, knife tube 200 is inserted into the handle 22. Handle 22comprises compression fingers 23 for gripping the knife tube 200 and athreaded region 24 as shown in FIG. 3A for the attachment of a clampingnut 25 as shown in FIG. 3B. The clamping nut 25 is tightened on thethreads 24 such that the knife tube 200 is contacted and securely heldby the compression fingers 23 of the handle 22. FIG. 3C is across-section view of the handheld endoscopic knife assembly when viewedalong the line Y-Y in FIG. 3B in the direction of the arrows. FIG. 3Cshows the contacting of the compression fingers against the knife tube200 as the compression nut 25 is tightened on the threads 24 of thehandle 22.

FIG. 3D is an end view from the knife blade end of an exemplaryendoscopic knife assembly showing the blade 100, knife tube 200 andcompression nut 25. FIG. 3E is an end view from the handle end of anexemplary endoscopic knife assembly showing the handle 200, knife tube200 and compression nut 25.

Referring now to FIGS. 3C-E in particular, in some embodiments, theknife tube 200 and handle 22 each comprise a hollow center lumen thatallows the insertion of an endoscopic visualization device, such as anarthroscope. Insertion of a visualization device into the knife tubeallows for the direct visualization of the knife blade and bodilytissues as the endoscopic knife assembly is being inserted into acannula, as a cut is made of a tissue, such as separation of a tendon,and/or as the endoscopic knife assembly is being withdrawn.

While one particular embodiment of handle having four flattened surfacesfor gripping the handle is depicted here, the physical design of thehandle 22 is not intended to be limited to the embodiment as depicted inFIGS. 3A-C and E. Rather, the present application contemplates anydesign of handle 22 that serves the purpose of allowing a practitionerto grip the handle 22 for the use of the endoscopic knife assembly.Similarly, while one particular embodiment of compression nut havingthree gripping surfaces for turning the nut is depicted here, thephysical design of compression nut 25 is not intended to be limited tothe embodiment as depicted in FIGS. 3B-E. Rather, the presentapplication contemplates any design of compression nut 25 that servesthe purpose of holding the knife tube 200 in a handle for the use of theendoscopic knife assembly.

In some alternative embodiments, as exemplified in FIGS. 4A-D, the knifetube is part of a handheld endoscopic knife assembly, having at least ablade 100, a knife tube 200 and a handle, wherein the handle 22 has beenaffixed to the knife tube by adhesive means. As used herein, “adhesivemeans” refers to the bonding of the handle to the knife tube through theuse of glue, epoxy, resin, solvents, laser or heat. For example, asdepicted in FIG. 4D, which is a is a cross-section view of the handheldendoscopic knife assembly when viewed along the line Z-Z in FIG. 4C inthe direction of the arrows, the area 26 between the slits 21 and theback end of the knife tube 200 provides a surface for the application ofan epoxy.

While one particular embodiment of handle having two opposingprotrusions for gripping the handle is depicted here, the physicaldesign of the handle 22 is not intended to be limited to the embodimentas depicted in FIGS. 4A-D. Rather, the present application contemplatesany design of handle 22 that serves the purpose of allowing apractitioner to grip the handle 22 for the use of the endoscopic knifeassembly. Furthermore, the present application contemplates any designof handle 22 for attaching to the knife tube by adhesive means whetheror not the handle comprises compression fingers or a threaded region.

In another aspect of the present application, the endoscopic knifeassembly comprises a knife tube that is configured for lockingattachment of the endoscopic knife assembly to an endoscope.

FIGS. 5A-D show an endoscopic assembly with a blade 100 mounted on aknife tube 200. As shown in FIG. 5A, the hook blade 100 is attached tothe knife tube 200 having an alignment ring 250, such that the blade 100is welded to the knife tube 200.

The knife tube 200 can optionally be marked on the top or side surfacewith gradations as exemplified in FIG. 5B to show the distance 41 to thedistal end of the knife tube, or to a specific point on the leading edgeof the cutting surface. As a non-limiting example, major gradations 42can be made to show each centimeter in distance from the distal end ofthe knife tube, with minor gradations 43 between them to show each 1, 2,2.5 or 5 millimeters. While the gradations can be applied to the knifetube by any means known in the art, it is preferable to lasermark thegradations on the knife tube 200 for accuracy and permanence.Additionally, the knife tube 200 can also be marked in a similar mannerwith additional information, for example on the bottom or a side surfaceof the knife tube 200. Exemplary markings may include, but are notlimited to, a maker's mark, part number, lot number and an indicationthat the endoscopic knife assembly is intended for only a single use.

Referring to FIG. 5A-C, showing side, top and bottom views of theendoscopic knife assembly, an alignment ring 250 is affixed near theproximate end of the knife tube 200. In one embodiment, the alignmentring 250 is affixed in position on the knife tube 200 using USP Class VIgamma irradiation and steam resistant epoxy adhesive during assembly. Insome embodiments, a two part epoxy such as MASTERBOND EP42 HT™ orARMSTRONG C-7™, or a suitable equivalent thereof is used. In oneembodiment, the distance 44 between the alignment ring 250 and theproximate end of the knife tube 200 is between about 15 mm and about 25mm. In another embodiment, the distance 44 is between about 18.67 mm andabout 19.43 mm. In another embodiment, the distance 44 is about19.05+/−0.38 mm.

As shown in FIGS. 5A-D, in particular embodiments, the alignment ring250 comprises a flattened surface 252 that is aligned on the oppositeside of the knife tube 200 as the blade 100. the plane of the flattenedsurface 252 of the alignment ring 250 is oriented perpendicular to theplane in which the blade is affixed to the knife tube 200.

The knife tube further comprises slots 45 in the proximate end that arepositioned on the sides of the knife tube 200, perpendicular to theblade mounted on the top of the knife tube. The slots 45 in particularembodiments extend forward to where the alignment ring 250 is affixed tothe knife tube 200. In some applications, the slots 45 may not extendforward to where the alignment ring 250 is affixed to the knife tube200. In one embodiment, the slots 45 have a width of between about 0.4mm and about 1.1 mm wide, more particularly between about 0.53 mm andabout 0.91 mm wide. Even more particularly, the width of the slots 45 isabout 0.66 mm.

The slots and alignment ring provide an attachment point for a lockingdevice, in order to mount an endoscope to the scope-mounting blade orendoscopic knife assembly.

Referring to FIGS. 5A-C, in some embodiments, the knife tube 200 has aflared proximate end 46. In one embodiment, about 0.2 to about 0.5 mostproximate millimeters of the knife tube 200 are flared. In anotherembodiment, about the 0.38 most proximate millimeters of the knife tube200 are flared. In another embodiment, the flared proximate end 46 has aflare angle of about 20 to 40 degrees, more particularly about 30degrees. In still another embodiment, the outer diameter of the flaredproximate end 46 of the knife tube is about 0.25 mm to about 0.45 mm,more particularly about 0.36 mm to about 0.37 mm.

Referring now to FIG. 5D, the inner diameter of the knife tube 200 issuch that an endoscope or arthroscope camera can be inserted into theknife tube in order to show the blade and the target tissue during aprocedure. In one embodiment, the inner diameter is between about 2 mmand about 3.5 mm. In a particular embodiment, the inner diameter isbetween about 2.6 mm and about 3.0 mm. In a more particular embodiment,the inner diameter is about 2.8 mm.

FIGS. 6A-D show an alternative embodiment of an endoscopic assembly witha blade 100 mounted on a knife tube 200. As shown in FIG. 6A, the hookblade 100 is attached to the knife tube 200 having an alignment ring250, such that the blade 100 is welded to the knife tube 200.

The knife tube 200 can optionally be marked on the top or side surfacewith gradations as exemplified in FIG. 6B to show the distance 41 to thedistal end of the knife tube, or to a specific point on the leading edgeof the cutting surface. As a non-limiting example, major gradations 42can be made to show each centimeter in distance from the distal end ofthe knife tube, with minor gradations 43 between them to show each 1, 2,2.5 or 5 millimeters. While the gradations can be applied to the knifetube by any means known in the art, it is preferable to lasermark thegradations on the knife tube 200 for accuracy and permanence.Additionally, the knife tube 200 can also be marked in a similar mannerwith additional information, for example on the bottom or a side surfaceof the knife tube 200. Exemplary markings may include, but are notlimited to, a maker's mark, part number, lot number and an indicationthat the endoscopic knife assembly is intended for only a single use.

Referring to FIG. 6A-C, showing side, top and bottom views of theendoscopic knife assembly, an alignment ring 250 is affixed near theproximate end of the knife tube 200. In one embodiment, the alignmentring 250 is affixed in position on the knife tube 200 using USP Class VIgamma irradiation and steam resistant epoxy adhesive during assembly. Insome embodiments, a two part epoxy such as MASTERBOND EP42 HT™ orARMSTRONG C-7™, or a suitable equivalent thereof is used. In oneembodiment, the distance 44 between the alignment ring 250 and theproximate end of the knife tube 200 is between about 15 mm and about 25mm. In another embodiment, the distance 44 is between about 18.67 mm andabout 19.43 mm. In another embodiment, the distance 44 is about19.05+/−0.38 mm.

As shown in FIGS. 6A-D, in particular embodiments, the alignment ring250 comprises a flattened surface 252 that is aligned on the same sideof the knife tube 200 as the blade 100. the plane of the flattenedsurface 252 of the alignment ring 250 is oriented perpendicular to theplane in which the blade is affixed to the knife tube 200.

The knife tube further comprises slots 45 in the proximate end that arepositioned on the sides of the knife tube 200, perpendicular to theblade mounted on the top of the knife tube. The slots 45 in particularembodiments extend forward to where the alignment ring 250 is affixed tothe knife tube 200. In some applications, the slots 45 may not extendforward to where the alignment ring 250 is affixed to the knife tube200. In one embodiment, the slots 45 have a width of between about 0.4mm and about 1.1 mm wide, more particularly between about 0.53 mm andabout 0.91 mm wide. Even more particularly, the width of the slots 45 isabout 0.66 mm.

The slots and alignment ring provide an attachment point for a lockingdevice, in order to mount an endoscope to the scope-mounting blade orendoscopic knife assembly.

Referring to FIGS. 6A-C, in some embodiments, the knife tube 200 has aflared proximate end 46. In one embodiment, about 0.2 to about 0.5 mostproximate millimeters of the knife tube 200 are flared. In anotherembodiment, about the 0.38 most proximate millimeters of the knife tube200 are flared. In a particular embodiment, the angle of the flare isbetween about 40 and 80 degrees, more particularly between about 50 and70 degrees, and still more particularly about 60 degrees. In stillanother embodiment, the outer diameter of the flared proximate end 46 ofthe knife tube is about 0.25 mm to about 0.45 mm, more particularlyabout 0.36 mm to about 0.37 mm.

Referring now to FIG. 6D, the inner diameter of the knife tube 200 issuch that an endoscope or arthroscope camera can be inserted into theknife tube in order to show the blade and the target tissue during aprocedure. In one embodiment, the inner diameter is between about 2 mmand about 3.5 mm. In a particular embodiment, the inner diameter isbetween about 2.6 mm and about 3.0 mm In a more particular embodiment,the inner diameter is about 2.8 mm.

FIGS. 7A-C are perspective views of a knife tube 200 without an affixedblade or alignment ring and without gradations.

FIG. 7A is a perspective view from the side of a knife tube 200. In aparticular embodiment, the outer diameter 51 of the knife tube 200 isbetween about 2.8 mm and about 3.6 mm, preferably between about 3.073 mmand about 3.175 mm. In a more preferred embodiment, the outer diameter144 is about 3.14+/−0.03 mm. In a still more preferred embodiment, theouter diameter 144 is about 3.14+/−0.01 mm.

In another particular embodiment, the posterior end of the knife tube200 is flared 46 In particular, the about 0.2 to about 0.6 mostposterior millimeters of the knife tube 200 are flared. In a moreparticular embodiment, the about 0.38 or about 0.38 to about 0.54 mostposterior millimeters of the knife tube 200 are flared. In a still moreparticular embodiment, about the 0.46 most posterior millimeters of theknife tube 200 are flared. In a particular embodiment, the angle 53 ofthe flare is between about 40 and 80 degrees, more particularly betweenabout 50 and 70 degrees, and still more particularly about 60 degrees.In still another preferred embodiment, the outer diameter 54 of theflared portion 46 of the knife tube 200 is between about 0.25 mm andabout 0.45 mm, more particularly between about 0.3 mm and about 0.4 mm,and still more particularly about 0.358 mm.

FIG. 7B is a perspective view from the top or bottom of a knife tube. Ina particular embodiment, the length 52 of the knife tube 200 is betweenabout 20 mm and about 100 mm. In a further particular embodiment, thelength 52 of the knife tube 200 is between about 30 mm and about 80 mm.In a still further particular embodiment, the length 52 of the knifetube 200 is between about 40 mm and about 70 mm. In a yet furtherparticular embodiment, the length 52 of the knife tube 200 is betweenabout 50 mm and about 60 mm. In a more particular embodiment, the length52 of the knife tube 200 is about 55 mm.

FIG. 7C is a perspective view of the posterior end of a knife tube 200,showing the slots 45 and the flared end. In particular embodiments, theslots 45 are between about 0.4 mm and about 1.1 mm wide, moreparticularly between about 0.53 mm and about 0.91 mm wide. Even moreparticularly, the width 148 of the slots is about 0.66 mm.

FIGS. 8A-D show an embodiment of the alignment ring 250 of theendoscopic knife assembly of the application. Referring now to FIG. 8A,in one embodiment, the alignment ring 250 has a flattened surface 252that, when the alignment ring 250 is affixed to the knife tube 200, isoriented on the bottom of the knife tube 200, i.e., opposite of themounting of the blade 100, as also shown in FIG. 5D; or is oriented onthe top of the knife tube 200, i.e., on the same side of the mounting ofthe blade 100, as also shown in FIG. 6D. When the endoscopic knifeassembly is fully assembled, the flattened surface 252 of the alignmentring forms a right angle with the vertical orientation of the affixedblade 100.

In one embodiment, the inner diameter 61 of the alignment ring, whichmust fit on the outside of the knife tube 200, is between about 2.6 mmand about 3.7 mm, particularly between about 3.0 mm and about 3.4 mm. Ina more particular embodiment, the inner diameter 61 is about 3.2+/−0.2mm. In a still more particular embodiment, the inner diameter 51 isabout 3.2+/−0.05 mm.

In a particular embodiment, the outer diameter 62 of the alignment ringis between about 6 mm and about 10 mm, more particularly between about7.3 mm and about 7.9 mm. In a still more particular embodiment, theouter diameter 62 is about 7.62+/−0.2 mm. In a still more particularembodiment, the outer diameter 62 is about 7.62+/−0.05 mm.

As shown in FIG. 8B, in one embodiment, the distance 63 between theinner opening of the alignment ring and the flattened surface 252, on aline perpendicular to the flattened surface 252, is between about 0.25mm and about 0.5 mm, more particularly between about 0.30 mm and about0.45 mm. In a still more particular embodiment, the distance 63 is about0.38 mm.

Referring to FIG. 8C, showing a side view of the alignment ring, andFIG. 8D, showing a view from the top of the alignment ring, in oneembodiment, the alignment ring 250 has a thickness 64 of between about1.0 mm and about 4.0 mm. In a particular embodiment, the thickness 64 isbetween about 2.0 mm and about 3.0 mm. In a more particular embodiment,the thickness 64 is about 2.54 mm.

Instrument Kit

Another aspect of the present application relates to an instrument kitfor implementing an endoscopic surgical procedure. The instrument kitcontains an endoscopic knife assembly having a low-profiledownward-angled blade, a cannula guide member comprising a longitudinalbore having open proximal and distal ends and an open slot extendingalong the length thereof communicating with the open ends, and anelongate insertion member that is slidably receivable within the cannulaguide member and is configured so that at least portions thereof conformwith the open distal end and the open slot of the guide member to form asmooth exterior surface in combination therewith.

In one embodiment, the instrument kit further includes an endoscopesized for insertion into the cannula guide member for directvisualization of an operative site.

In another embodiment, the endoscope is capable to carry a cuttinginstrument at a leading end. The endoscope is insertable into thecannula guide member such that the cutting instrument protrudes throughthe open slot in the cannula guide member.

In another embodiment, the instrument kit further includes an elevator.

In another embodiment, the instrument kit further includes a depth gaugemountable to a leading end of the endoscope.

In another embodiment, the instrument kit further includes a lockingdevice capable of locking the endoscope and the cannula guide memberinto mutually fixed positions.

In another embodiment, the instrument kit further includes a stop devicemountable on the cannula guide member to prevent excessive penetrationat a surgical site by the cutting instrument. In another embodiment, theinstrument kit further includes a curved dissector.

Methods

Another aspect of the present application relates to a method foruniportal endoscopic surgery. Uniportal endoscopic surgery allows thepractitioner to visualize a target tissue and its surrounding tissues aswell as perform a surgical procedure through a single entry portal. Insome instances, the entry portal may be a natural opening, while inother instances the entry portal is an incision. In the case of anincision, generally only a single small incision must be made. Inparticular embodiments, the incision is less than or equal to about 2 cmin length. In more particular embodiments, the incision is less than orequal to about 1.5 cm in length. In still more particular embodiments,the incision is less than or equal to about 1 cm in length. The singlesmall incision allows the patient to recover more quickly and begintherapy and/or resume normal activity as tolerated sooner.

The uniportal endoscopic surgical procedure described herein can be usedto implement a number of different surgical procedures. In someembodiments, the uniportal endoscopic surgical procedure is selectedfrom the group consisting of trigger finger release, carpal tunnelrelease, cubital tunnel release, plantar fascia release, lateral releasefor patella realignment, release of the extensor tendons, release of theposterior and other compartments of the leg, and forearm fascialrelease.

One aspect of the present application relates to a method for aperforming auniportal endoscopic surgical procedure a target tissue in asubject. Generally, following the establishment of an entry portal, insome embodiments a blunt instrument, such as an elevator is insertedthrough the portal to establish an opening in the underlying tissuebetween the portal and the target tissue.

A cannula having open proximal and distal ends and an open slotextending along the length of the cannula is inserted into the entryportal and extended through to the target tissue. In particularembodiments, the cannula is made of a clear plastic material so that theentirety of the surrounding tissue can be viewed with an arthroscope. Inorder to facilitate insertion of the cannula, the central lumen of thecannula comprises an obturator, which is withdrawn following insertionof the cannula.

An arthroscope is inserted into the cannula to view the target tissueand the surrounding tissues, assuring that the slot of the cannula is inproper orientation to the target tissue. The arthroscope is withdrawnand an arthroscope with a mounted endoscopic knife assembly having alow-profile blade that has a downward angled cutting surface that isradiused at its upper end is advanced into the cannula, with the knifeblade aligned with the slot of the cannula. In some embodiments, thearthroscope used for viewing the target tissue and the surroundingtissues is the same unit as the arthroscope comprising a mountedendoscopic knife assembly. In other embodiments, the arthroscope usedfor viewing the target tissue and the surrounding tissues is a differentunit from the arthroscope comprising a mounted endoscopic knifeassembly.

The arthroscope comprising a mounted endoscopic knife assembly isadvanced further through the cannula so that the blade moves in contactwith the target tissue through the slot, operatively engaging the targettissue with the blade. The blade is further advanced through the cannulato divide the target tissue.

In one particular embodiment, the operative procedure is trigger fingerrelease.

In another particular embodiment, the establishing an entry portalcomprises making an incision.

In another particular embodiment, the target tissue is the A1 pulley.

In another particular embodiment, the inserting of said arthroscopecomprising an endoscopic knife assembly having a low-profile blade thathas a downward angled cutting surface that is radiused at its upper endis followed by the insertion of an arthroscope comprising a means forvisualization of the results of the endoscopic surgical procedure on thetarget tissue.

The present invention is further illustrated by the following exampleswhich should not be construed as limiting. The contents of allreferences, patents and published patent applications cited throughoutthis application, as well as the Figures and Tables, are incorporatedherein by reference.

Example 1 Uniportal Endoscopic Trigger Release

In a patient presenting with trigger finger of the middle or ringfinger, a 1 cm incision is made just proximal to the A1 pulley on thedistal palmar crease proximate to the affected digit.

An elevator is introduced into the incision and used to create a planesuperficial to the flexor tendon sheath. The elevator is withdrawn.

A slotted cannula with an obturator inserted therein is introduced intothe incision and advanced through the plane created by the elevator. Theslot of the cannula is oriented facing the flexor tendon sheath. Theobturator is removed from the cannula.

An arthroscope is introduced into the cannula and advanced to visualizethe A1 pulley and A2 pulley as shown in FIGS. 9A-B. The arthroscope iswithdrawn.

An endoscopic knife assembly having a low-profile downward-angled bladeis fastened onto an arthroscope.

The scope and blade assembly is advanced into the cannula, dividing theA1 pulley. Having the endoscopic knife assembly mounted directly on thearthroscope allows direct visualization of the procedure from thepoint-of-view of the blade, allowing visualization of the A2 pulley andavoiding damage to the A2 pulley (FIGS. 10A-B). The scope and bladeassembly is withdrawn from the cannula.

An arthroscope is again advanced into the cannula to visualize the cutedges of the A1 pulley, as well as visualization of the underlyingflexor tendon (FIGS. 11A-B).

While visualizing the tendon, release of the tendon is confirmed bypassive manipulation of the digit through its range of motion.

The absence of triggering is confirmed by having the subject flex andextend the affected digit.

The arthroscope is withdrawn and the cannula is removed from theincision.

The wound is closed and a soft bandage is applied.

The patient is encouraged to begin early finger motion following surgeryand to resume daily activities as tolerated.

The above description is for the purpose of teaching the person ofordinary skill in the art how to practice the present invention, and itis not intended to detail all those obvious modifications and variationsof it which will become apparent to the skilled worker upon reading thedescription. It is intended, however, that all such obviousmodifications and variations be included within the scope of the presentinvention, which is defined by the following claims. The claims areintended to cover the components and steps in any sequence which iseffective to meet the objectives there intended, unless the contextspecifically indicates the contrary.

1-7. (canceled)
 8. An endoscopic knife assembly, comprising: a knifetube having a distal end and a proximate end and a low-profile bladethat has a downward angled cutting surface that is radiused at its upperend attached to the distal end.
 9. The endoscopic knife assembly ofclaim 8, further comprising a handle at the proximate end of the knifetube.
 10. The endoscopic knife assembly of claim 9, wherein the handlecomprises compression fingers for gripping the knife tube and a threadedregion for the attachment of a clamping nut.
 11. The endoscopic knifeassembly of claim 9, wherein the handle is bonded to the knife tube. 12.The endoscopic knife assembly of claim 11, wherein the handle is bondedwith epoxy.
 13. The endoscopic knife assembly of claim 8, wherein theknife tube comprises an alignment ring attached near the proximate endand one or more slots at the proximate end for the attachment of alocking assembly to the knife tube and alignment ring.
 14. Theendoscopic knife assembly of claim 13, wherein the slots are located ona plane that is perpendicular to the blade attached to the distal end ofthe knife tube.
 15. The endoscopic knife assembly of claim 13, whereinthe alignment ring comprises a flattened surface that is positionedperpendicular to the hook blade attached to the distal end of the knifetube.
 16. The endoscopic knife assembly of claim 8, wherein the knifetube is marked on the top or side surface with gradations.
 17. Theendoscopic knife assembly of claim 8, wherein the blade is welded to theknife tube.
 18. An instrument kit for implementing an endoscopicsurgical procedure comprising: an endoscopic knife assembly comprising alow-profile blade that has a downward angled cutting surface that isradiused at its upper end and a knife tube.
 19. The instrument kit ofclaim 18, wherein the endoscopic knife assembly further comprises ahandle at the proximal end of the knife tube.
 20. The instrument kit ofclaim 19, wherein the handle comprises compression fingers for grippingthe knife tube and a threaded region for the attachment of a clampingnut.
 21. The instrument kit of claim 19, wherein the handle is bonded tothe knife tube.
 22. The instrument kit of claim 18, wherein the knifetube comprises an alignment ring attached near the proximate end and oneor more slots at the proximate end for the attachment of a lockingassembly to the knife tube and alignment ring.
 23. The instrument kit ofclaim 18, further comprising a cannula having an open slot extendingalong the length of the cannula.
 24. The instrument kit of claim 23,wherein the cannula is a clear cannula.
 25. The instrument kit of claim18, further comprising an obturator, an elevator and/or an arthroscope.26-27. (canceled)